# Non-local signatures of the chiral magnetic effect in Dirac semimetal Bi$_{0.97}$Sb$_{0.03}$

## TL;DR

This study investigates the chiral magnetic effect in Dirac semimetal Bi$_{0.97}$Sb$_{0.03}$ using local and non-local measurements, revealing a long-lived chiral charge polarization indicative of topological properties.

## Contribution

It provides experimental evidence of non-local signatures of the chiral magnetic effect in a Dirac semimetal, highlighting the extended lifetime of chiral charge polarization.

## Key findings

- Chiral charge relaxation time exceeds Drude lifetime by over tenfold.
- Non-local measurements confirm the topological origin of the CME.
- Bi$_{0.97}$Sb$_{0.03}$ exhibits robust chiral magnetic signatures.

## Abstract

The field of topological materials science has recently been focussing on three-dimensional Dirac semimetals, which exhibit robust Dirac phases in the bulk. However, the absence of characteristic surface states in accidental Dirac semimetals (DSM) makes it difficult to experimentally verify claims about the topological nature using commonly used surface-sensitive techniques. The chiral magnetic effect (CME), which originates from the Weyl nodes, causes an $\textbf{E}\cdot\textbf{B}$-dependent chiral charge polarization, which manifests itself as negative magnetoresistance. We exploit the extended lifetime of the chirally polarized charge and study the CME through both local and non-local measurements in Hall bar structures fabricated from single crystalline flakes of the DSM Bi$_{0.97}$Sb$_{0.03}$. From the non-local measurement results we find a chiral charge relaxation time which is over one order of magnitude larger than the Drude transport lifetime, underlining the topological nature of Bi$_{0.97}$Sb$_{0.03}$.